Category: Articles

Dissolved organic matter (DOM) absorbance and fluorescence were used as optical proxies to track terrestrial DOM fluxes through estuaries and coastal waters by comparing models developed for several coastal ecosystems. Key to using these optical properties is validating and calibrating them with chemical measurements, such as lignin-derived phenols—a proxy to quantify terrestrial DOM. Utilizing parallel factor analysis (PARAFAC), and comparing models statistically using the OpenFluor database… Read more »

Iodine-131 (t1/2 = 8.04 d) is widely used in nuclear medicine, primarily to treat hyperthyroidism and thyroid cancer, with an annual average of 188 treatments per million people in developed countries. The administered dose of Iodine-131 (∼0.1−1 and 4−8 Gbq for hyperthyroidism and thyroid cancer, respectively) is metabolized by patients and eliminated from the body mostly in urine. In the United States, patient excreta are exempt… Read more »

Sediment organic carbon composition and provenance have been extensively studied in the Gulf of Mexico. Generally, inputs of terrestrially-derived organic carbon dominate near shore sediments and decrease with distance offshore where water column phytoplankton dominate contributions to shallow sediments. For this study shallow sediment and porewater samples were collected from Atwater Valley, Texas-Louisiana Shelf, Gulf of Mexico near a seafloor mound feature identified in geophysical surveys as… Read more »

The Chatham Rise is located offshore of New Zealand’s South Island. Vast areas of the Chatham Rise are covered in circular to elliptical seafloor depressions that appear to be forming through a bathymetrically controlled mechanism, as seafloor depressions 2–5 km in diameter are found in water depths of 800–1100 m. High-resolution P-Cable 3D seismic data were acquired in 2013 across one of these depressions. The seafloor… Read more »

The majority of coastal sediment carbon cycling studies have focused on contributions from autochthonous photosynthetic marine and allocthonous terrigenous inputs. However, hydrocarbons produced within deep sediment through thermochemical and microbiological conversions can significantly contribute to cycling of carbon, especially in shallower sediments and water column. Stable carbon isotope ratios indicative of petroleum and methane (CH4) origins are found in bacterioplankton biomarkers. In a related study in… Read more »

An expedition conducted on the USCG Polar Sea during August of 2009 explored the Alaskan Shelf of the Beaufort Sea to address the sediment methane sources, the potential for contribution to climate change and possible locations for energy exploration.  MITAS, lead by Dr. Richard Coffin, focused on spatial variation of methane in shallow sediments, the water column and flux to the atmosphere.  Scientists from the United States, Germany, and… Read more »

There is a strong national and financial rational for development of liquid natural gas (LNG) in China.  Transition to LNG, moving away from burning coal and oil, has potential to result in significantly less environmental impact.  Success on undertaking a $40 billion investment with a natural gas LNG project with Australia does entail a requirement to address a large range of potential changes in the environment. … Read more »

For Chinese exploration of potential methane hydrate loading in their coastal region Strategic Carbon (SC) LLC will provide methane hydrate site assessment prior to deep hydrate well drilling and logging.  This activity optimizes drill site selection and provides significant cost savings.  Typical borehole drilling and well logging costs 10-20 million USD.  An expedition that utilizes geochemical, geological, and geophysical analyses to guide borehole site selection can… Read more »

Future plans for Chinese sediment methane hydrate and petroleum mining, as well as carbon dioxide sequestration, require credible environmental assessments to confirm that anthropogenic compounds released to shallow sediment and the water column during mining will not adversely affect food chain cycling. These seeps could also cause gradual geothermal warming and have a subsequent impact on platform or coastal stability. Conversely, it is necessary to determine that… Read more »

In The Royal Society of Chemistry, 2013 By T. Boyd Carbon dioxide radiocarbon analysis has proved extremely useful in demonstrating on-site fossil fuel-derived contaminant remediation to a non-toxic end-product (CO2). At the North Island Naval Air Station in San Diego, CA (USA) fuel groundwater contamination assessed for source(s) and natural degradation with radiocarbon and stable carbon isotope analysis in 16 wells across a underground fuel contamination zone…. Read more »